Today was their concert in Mexico for their tour and Ravi suddenly passed out.
N tried to lift Ravi up after he collapsed and called the staffs
Leo and Ken were all dizzy at this point too and at the end they couldn't hold it anymore and went backstage.
Ken decided to come back on stage for their "Love equation" stage but Leo's condition was worse so he decided not to come out at all

Here's the video screencap where Ravi was trying to rap, he looked so worn out